Eren begins his training with the Cadet Corps, but questions about his painful past overwhelm him. When he struggles with a maneuvering exercise, Bertolt and Reiner offer kindly advice.

The Recon Corps moves Eren to an old abandoned castle where he will continue his training. Hange visits and reveals that she's been putting two captured Titans through a series of tests and trials — experiments that she wants Eren's help with.

Coupled with the military's cover-up of a previous incident, the shocking discovery inside the Walls causes a stir. Elsewhere, while the new Scout recruits are held for observation, a surprising threat appears.

The pursuit begins as the Recon Corps battles their way to Eren. But as the Scouts start to take numerous casualties, Erwin executes a risky strategy.